1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
#include "rail.h"
#include "game/network/link.h"
#include <GL/glew.h>
#include <array>
#include <cache.h>
#include <cmath>
#include <gfx/gl/shader.h>
#include <gfx/models/texture.h>
#include <gfx/models/vertex.hpp>
#include <glm/gtc/constants.hpp>
#include <glm/gtx/rotate_vector.hpp>
#include <glm/gtx/transform.hpp>
#include <glm/gtx/vector_angle.hpp>
#include <numbers>
#include <utility>
RailLinks::RailLinks() : texture {Texture::cachedTexture.get("rails.jpg")} { }
void RailLinks::tick(TickDuration) { }
static const auto identityModel {glm::identity<glm::mat4>()};
void
RailLinks::render(const Shader & shader) const
{
shader.setModel(identityModel);
texture->Bind();
links.apply(&RailLink::render, shader);
}
template<RailLinkConcept T>
std::shared_ptr<T>
RailLinks::addLink(glm::vec3 a, glm::vec3 b)
{
const auto node1 = *nodes.insert(std::make_shared<Node>(a)).first;
const auto node2 = *nodes.insert(std::make_shared<Node>(b)).first;
// TODO set end flag properly
return links.create<T>(Link::End {node1, true}, Link::End {node2, true});
}
template<RailLinkConcept T>
std::shared_ptr<T>
RailLinks::addLink(glm::vec3 a, glm::vec3 b, glm::vec2 centre)
{
const auto node1 = *nodes.insert(std::make_shared<Node>(a)).first;
const auto node2 = *nodes.insert(std::make_shared<Node>(b)).first;
// TODO set end flag properly
return links.create<T>(Link::End {node1, true}, Link::End {node2, true}, centre);
}
template std::shared_ptr<RailLinkStraight> RailLinks::addLink(glm::vec3, glm::vec3);
template std::shared_ptr<RailLinkCurve> RailLinks::addLink(glm::vec3, glm::vec3, glm::vec2);
void
RailLink::render(const Shader &) const
{
meshes.apply(&Mesh::Draw);
}
constexpr const std::array<std::pair<glm::vec3, float>, 4> railCrossSection {{
// ___________
// _/ \_
// left to right
{{-1.F, 0.F, 0.F}, 0.F},
{{-.75F, .25F, 0.F}, 0.125F},
{{.75F, .25F, 0.F}, 0.875F},
{{1.F, 0.F, 0.F}, 1.F},
}};
constexpr const glm::vec3 up {0, 1, 0};
constexpr const glm::vec3 north {0, 0, 1};
const auto oneeighty {glm::rotate(std::numbers::pi_v<float>, up)};
constexpr auto half_pi {glm::half_pi<float>()};
constexpr auto sleepers {5.F}; // There are 5 repetitions of sleepers in the texture
template<typename V>
auto
flat_orientation(const V & diff)
{
const auto flatdiff {glm::normalize(glm::vec3 {diff.x, 0, diff.z})};
auto e {glm::orientation(flatdiff, north)};
// Handle if diff is exactly opposite to north
return (std::isnan(e[0][0])) ? oneeighty : e;
}
template<typename V>
auto
flat_angle(const V & diff)
{
const auto flatdiff {glm::normalize(glm::vec3 {diff.x, 0, diff.z})};
return glm::orientedAngle(flatdiff, north, up);
}
template<typename T>
constexpr auto
round_frac(const T & v, const T & frac)
{
return std::round(v / frac) * frac;
}
template<typename T>
constexpr auto
round_sleepers(const T & v)
{
return std::round(v / sleepers) * sleepers;
}
RailLinkStraight::RailLinkStraight(End a, End b) : RailLink(std::move(a), std::move(b))
{
vertices.reserve(2 * railCrossSection.size());
indices.reserve(2 * railCrossSection.size());
const auto diff {ends[1].first->pos - ends[0].first->pos};
const auto len = round_sleepers(glm::length(diff) / 2.F);
const auto e {flat_orientation(diff)};
for (int ei = 0; ei < 2; ei++) {
const auto trans {glm::translate(ends[ei].first->pos) * e};
for (const auto & rcs : railCrossSection) {
const glm::vec3 m {(trans * glm::vec4 {rcs.first, 1})};
vertices.emplace_back(m, glm::vec2 {rcs.second, ei ? len : 0.F}, up);
if (vertices.size() > railCrossSection.size()) {
indices.push_back(vertices.size() - railCrossSection.size() - 1);
indices.push_back(vertices.size() - 1);
}
}
}
meshes.create<Mesh>(vertices, indices, GL_TRIANGLE_STRIP);
}
RailLinkCurve::RailLinkCurve(End a, End b, glm::vec2 c) : RailLink(std::move(a), std::move(b)), centre(c)
{
const auto & e0p {ends[0].first->pos};
const auto & e1p {ends[1].first->pos};
const glm::vec3 centre3 {centre.x, e0p.y, centre.y};
const auto diffa = centre3 - e0p;
const auto diffb = centre3 - e1p;
const auto anga = flat_angle(diffa);
const auto angb = [&diffb, &anga]() {
const auto angb = flat_angle(diffb);
return (angb < anga) ? angb + glm::two_pi<float>() : angb;
}();
const auto radius = glm::length(e0p - centre3);
const auto length = round_sleepers(radius * (angb - anga) / 2.F);
const auto segs = std::round(5.F * length / std::pow(radius, 0.7F));
const auto step {glm::vec3 {angb - anga, e1p.y - e0p.y, length} / segs};
const auto trans {glm::translate(centre3)};
auto addRcs = [this, trans, radius](auto arc) {
const auto t {trans * glm::rotate(glm::half_pi<float>() - arc.x, up)
* glm::translate(glm::vec3 {radius, arc.y, 0.F})};
for (const auto & rcs : railCrossSection) {
const glm::vec3 m {(t * glm::vec4 {rcs.first, 1})};
vertices.emplace_back(m, glm::vec2 {rcs.second, arc.z}, up);
}
};
for (glm::vec3 arc = {anga, 0.F, 0.F}; arc.x < angb; arc += step) {
addRcs(arc);
}
addRcs(glm::vec3 {angb, e1p.y - e0p.y, length});
for (auto n = 4U; n < vertices.size(); n += 1) {
indices.push_back(n - 4);
indices.push_back(n);
}
meshes.create<Mesh>(vertices, indices, GL_TRIANGLE_STRIP);
}
|
